Occupants in a motor vehicle desire to have cup holders located within convenient reach. In autonomous vehicles, rotatable seats pose a challenge to conveniently position cup holders within a comfortable, reachable distance of the vehicle passengers. More specifically, since the seat positions can change, cup holders on door trim or other fixed locations are not always conveniently located or readily accessible. In order to rectify this situation, a need is identified for an armrest for a motor vehicle seat incorporating a deployable cup holder as well as for a motor vehicle seat including such an armrest.